These days, Sharpe has fellow Republicans accusing him of abandoning the cause of leaner government as a Hillsborough County commissioner. They're calling him a turncoat, a closeted liberal or worse — a Charlie Crist wannabe seeking to change his stripes for the next political campaign.

His sins: backing increased home-building fees to pay for schools, promoting a sales tax hike for transit and, just last week, proposing a domestic partnership registry in Hillsborough.

"And it will work for Mark when he winds up being a Democrat," said Republican activist Sam Rashid, a critic of Sharpe.

Sharpe, 53, insists he doesn't have his eye on another office. Nor will he be changing parties. He says he's simply trying to solve problems at a time when fealty to party seems to trump all else. "I don't think that my political ideology has changed," he said. "I've always been a contrarian in terms of challenging what I considered to be the central tenets of whatever it is I'm doing."

With two years to go before he must leave due to term limits, he may just be finding his voice.

Republican political consultant Anthony Pedicini jokingly describes Sharpe as a Rubik's Cube, a puzzle at times who can be hard to solve. But he said he respects Sharpe's willingness to "jump into the breach when no one's there."

"Mark's not a cookie-cutter guy," Pedicini says.

Sharpe ran three times for Congress in the 1990s, the first when he was only 32, a former Navy intelligence officer and teacher seeking a Tampa-based seat heavily stacked with Democratic voters. The closest he came was on his second try in 1994, when Republicans rolled into Congress pledging to balance budgets and cut taxes, signing the Gingrich-promoted Contract with America pledge to do so.

He earned the hardliner label during the third congressional run. Sharpe slammed former state legislator and Democrat Jim Davis with a misleading television ad depicting him as a tax-and-spend liberal.

He emerged eight years later, in 2004, to run for a countywide County Commission seat being vacated by Democrat Pat Frank, now clerk of the circuit court. This time, things would be different — no attacks.

"I started throwing my talking points away," Sharpe said.

He said his main goal was to elevate the level of discourse on a board known for partisan backbiting and pettiness. He was going to be a problem solver.

He has made economic development the top priority. For Sharpe, that means moving away from an economy based on home building to one that lures high-tech businesses and entrepreneurs.

Business leaders say that in order to attract high-tech investors, a community must have quality schools. As home building boomed in the early 2000s, Sharpe parted with most of his fellow Republicans in 2006 to support a sharp increase on fees charged to home builders for new classrooms.

It was a move he said he disfavored as a candidate.

Midway through his tenure, Sharpe joined fellow Republican Ken Hagan on a task force to tackle Hillsborough's increasingly clogged roads. The group's stated goal was to come up with solutions without burdening homeowners with additional property taxes.

The task force would recommend a penny sales tax increase to pay for new roads, commuter light rail and more public buses. Again, Sharpe was a rail skeptic on the stump.

"Governing is different from campaigning," said Kevin Thurman, a former Democratic political consultant and transit advocate. "Now that he's in government, he's interested in results."

He was already hearing the word "traitor" hurled his way.

The transit tax was convincingly defeated by voters in 2010. Sharpe survived an intraparty challenge that same year from an opponent who made the support of rail his albatross.

His latest proposal may have elicited the strongest reaction yet. With no public warning, Sharpe called for the creation of a domestic partnership registry. It would have allowed committed but unmarried couples — gay or straight — to declare their relationship, ensuring they can make decisions for a loved one who is sick or has died. Social conservatives call it a step toward gay marriage. Fiscal conservatives argue it would have been an expansion of government.

Pinellas County and the cities of Tampa, St. Petersburg and Clearwater had passed their own versions in the past year.

Sharpe responded to criticism on Facebook, as he is apt to do: "Allowing people to register their emergency contact or guardianship designee … is no more advancing the 'homosexual agenda' than to issue a library card," he wrote. "Small government should never ask of citizens why they choose to make the decisions they make, but merely afford all citizens equal protection under the law."

What does it mean for Sharpe's future political ambitions? Absolutely nothing, he insists.

Various rumors have him considering a run for mayor of Tampa, or perhaps another try at Congress.

"Honestly, I have no master plan," Sharpe said. "I'm going to be the anti-Charlie Crist. I've got two more years and I'm going to concentrate on pouring myself into being the best commissioner I can be."